2sums c++

#include <bits/stdc++.h>
using namespace std;

#define IOS ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
#define endl '\n'
#define ll long long    // range : -9*10^18 ~ 9*10^18



class Solution {
public:
    vector<int> twoSum(vector<int>& nums, int target) {
        unordered_set<int> s;
        vector<int> ans;
        for(auto e : nums){
            cout << e << endl;
        }
        for(int i=0; i<nums.size(); i++){
            auto search = s.find(nums[i]);
            if(search != s.end()){
                ans.push_back(nums[i]);
                ans.push_back(*search);
                break;
            }else{
                s.insert(nums[i]);
            }
        }
        for(auto e : s){
            cout << e << endl;
        }
        return ans;
    }
    void prac(){
        cout << "hello world" << endl;
    }
};

int main(){
    IOS;

    Solution sol = Solution();
    vector<int> input {2, 7, 11, 15};
    int target = 9;

    vector<int> ans = sol.twoSum(input, target);
    cout << ans[0] << ' ' << ans[1];

    // sol.prac();

    return 0;
}